Valve manufacturing process
The production of valves is usually carried out in 5 stages of casting, machining, polishing, plating and assembly.
The primary material used in castings and valves is rice alloys. Rice is an alloy of copper and zinc, the ratio of which in the alloy determines the type of rice according to its use. Because of its special applications and its shape and color, it is used in many places and is used in the sanitary hygiene industry because of its oxidation resistance. Rice alloys are known as yellow brass, resistant to fading and staining. The copper in the rice gives it a microbial property.
Casting includes 3 types of molds and die casting molds and special molds. Casting is made of the same traditional casting sand, in which single-use sandwich molds are made of sand, and after melting and cooling in the sand, the desired product is obtained, the quality of the surfaces obtained by this method is very low It has plenty of pores and even has a rugged surface even after payment. The die casting process is also used to make aluminum and zinc alloys. Casting using special molds is one of the best and most quality casting methods, with high quality and high quality valves mainly produced by this method. The mold is usually heated before the molding, and the mold temperature must always be monitored to produce high quality casting components. Other advantages of this method are good dimensional accuracy, good finished surface, high metallurgical quality of parts and low casting imperfections.
Machining is the shaping of the piece from the casting step by cutting and cutting with tool tools. The machining of parts is based on the type of work of milling machines, milling, drill, plate and simple drill.
Self-polishing has two steps, sandblasting and polishing. In the foaming step, the surface of the machined parts is washed with a twist of the toothbrush to smooth and smooth the workpieces and surface roughness. Then, in the polish section, along with the polish waxes, the surface is glossy and glossy to prepare for the plating phase.
The electroplating process has three parts for the preparation of parts, nickel plating and hot plating.
Preparation of parts for plating
To obtain an appropriate metal surface for electroplating, the first action to be taken with care is to clean the piece. Because good adhesion occurs when the base metal has a perfectly clean surface. Because of this, all layers or other disturbing circles, such as dirt, oily wax stains, oxide layers that are created on a high-grade piece should be eliminated. Preparation operations include, fumigation, cleaning by dilute acid and rinsing.
The white colored nickel is similar to silver, which is a little yellowish and is easily polished and has an expansion, contraction, and magnetism. Nickel plating is essentially intended to create a glossy layer for a subsequent layer, such as chromium, to provide good surface fineness and corrosion resistance for brass parts, and even for metals that are metallized by chemical methods. In the nickel plating phase, the piece is kept in the electrolyte bath so that a layer of nickel is formed at a thickness of at least 10 microns on it.
The chromium-plated coatings are similar to silver, white to blue. The reflection power of the chromed and completely polished surface is 65%. This number is 88% for silver and 55% for nickel. While the reflection property of silver and nickel is lost over time, chromium does not change. Chromium layers can not be welded and do not accept coloring and painting. Chrome is resistant to gases, alkaline and salts. It is therefore a very good cover for sanitary valves. But it is weak against acids. For this reason, the valves should only and only use diluted water vinegar. Due to the fact that the electrolytic chrome coatings do not completely cover the electroplating surface, hence the use of decorative chrome works is never used alone, but always as a final coating on a coat that guarantees surface protection against corrosion. . Usually used as a nickel protector base. In the chromed plating stage, the chamber is kept to a sufficient degree in the electrolyte bath to form a layer of chromium with a thickness of at least 0.3 microns on it.
In the assembly stage, the lever hygiene valves are installed on the valves after controlling the appearance of the plating unit. Most European cartridges are installed on the valves. The pressure test is then carried out under pressure of 5 atmospheres according to the national standard of Iran. After the test, the valves are dry and cleaned and then divided and ready to be supplied to the consumer.
Cartridges that have the same brain point in the classical valves, cut down the water flow through the lever up and down, and have different types, which is the best grade of the filtered ceramic cartridge. Typically, cartridges are extraneous, and the brands of Sedal, Citoc, and Crap are more famous.
Storage conditions after execution